Crystalline Admixture Cuts 60 Days from Croatian Rail Tunnel Repair
Orlando – October 16, 2026 -- A crystalline waterproofing admixture removed roughly 60 days of planned waterproofing work from the rehabilitation of the Dujmovača Tunnel in Split, Croatia, and cut water penetration depth by 83% after ten test cycles, according to Penetron Group.
Redesign followed material shortage and failed adhesion tests
The Dujmovača Tunnel (M604) is part of the Split suburban railway line and is one of two railway tunnels beneath the city center. The rehabilitation targeted waterproofing and drainage to control water ingress. The original design specified a dimpled membrane system to channel inflows through drains and half-pipes into a drainage channel.
Two problems forced a rethink. The specified composite drainage material was no longer available, and shotcrete adhesion tests returned values below the required threshold, said Theodor Mentzikofakis, Managing Director and Partner of Penetron Hellas.